The instant invention provides the isopropyl substituted cyclohexenyl methyl ketones defined according to the structure: ##STR2## wherein R.sub.1, R.sub.2, R.sub.11 and R.sub.21 each represents hydrogen or methyl with the provisos that:
(a) at least two of R.sub.1, R.sub.21, R.sub.2 and R.sub.11 represent hydrogen; PA1 (b) either R.sub.2 is methyl and R.sub.21 is hydrogen or R.sub.21 is methyl and R.sub.2 is hydrogen; and PA1 (c) R.sub.1 is methyl only when R.sub.2 is methyl and R.sub.11 is methyl only when R.sub.21 is methyl
and uses thereof for their organoleptic properties in consumable materials.
Substances which provide powerful musty, musky, camphoraceous, rosy, green, spicy (cubeb/peppery), woody and caryophyllene-like aromas with buttery and spicy topnotes are highly desirable in the art of perfumery. Many of the natural materials which provide such fragrances and contribute such desired nuances to perfumery compositions are high in cost, vary in quality from one batch to another and/or are generally subject to the usual variations of natural products.
Methyl substituted acetyl cyclohexene derivatives are well known in the art of perfumery.
Thus, Arctander "Perfume and Flavor Chemicals (Aroma Chemicals)", Volume I, at Monograph 1000 describes the perfumery utilities of 1,1-dimethyl-cycolhex-3-enyl methyl ketone defined according to the structure: ##STR3## At Monograph 1000, Arctander states that the compound having the structure: ##STR4## has a powerful, herbaceous, somewhat weedy, but basically sweet odor of moderate tenacity. Arctander states that this ketone occurs as a minor component in the reaction mixture from treatment of myrcene hydrochloride with acetylating agents.
Methyl substituted acetyl cyclohexene derivatives are also known as intermediates for preparation of other perfumery materials. Thus, the compounds having the structures: ##STR5## are described in U.S. Pat. No. 4,289,659 issued on Sept. 15, 1981 (Schulte-Elte, et al).
Furthermore, the genus of compounds defined according to the structure: ##STR6## wherein R.sub.5 represents methylethyl or propyl are disclosed as intermediates for the preparation of synthetic plant growth promoters by Kujatova-Shemyakina, et al, Chem.Abstracts, Volume 74, 1971, 111613c.
The compounds of our invention are produced via a Diels-Alder reaction between a diene such as isoprene or methyl isoprene and a dienophile which is a ketone, specifically 2-methyl-3-hexen-5-one according to the reaction: ##STR7## wherein R represents methyl or ethyl and R.sub.1, R.sub.21, R.sub.2 and R.sub.11 have been defined, supra. The reaction of our invention can be carried out thermally at higher temperatures or in the presence of a Lewis acid catalyst at lower temperatures. The prior art contains reactions between aldehyde dienophiles and isoprene derivatives, for example, the reaction: ##STR8## as disclosed in U.S. Pat. No. 4,424,379, at columns 14 and 15 thereof.
The resulting aldehydes in U.S. Pat. No. 4,424,379 are used for their properties as intermediates in producing perfumery materials by means of such reactions as aldol condensations.
Nothing in the prior art however, implicitly or explicitly indicates that the isopropyl substituted cyclohexenyl methyl ketones of our invention or compounds obvious to the isopropyl substituted cyclohexenyl methyl ketones of our invention are useful for their organoleptic properties particularly in augmenting or enhancing the aroma of perfume compositions, colognes and/or perfumed articles.